Merge pull request #2112 from jedgarpark/breakbeat-breadboard

first commit audio mixer breakbeats

Author: TheKitty

Breakbeat_Breadboard/code.py

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+# SPDX-FileCopyrightText: 2022 John Park for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+# Breakbeat Breadboard based on:
+# @todbot / Tod Kurt - https://github.com/todbot/plinkykeeb
+# Convert files to appropriate WAV format (mono, 22050 Hz, 16-bit signed) with command:
+#  sox loop.mp3 -b 16 -c 1 -r 22050 loop.wav
+# put samples in "/wav" folder
+
+import time
+import board
+import keypad
+import audiocore
+import audiomixer
+from audiopwmio import PWMAudioOut as AudioOut
+
+# wait a little bit so USB can stabilize and not glitch audio
+time.sleep(3)
+
+# list of (samples to play, mixer gain level)
+wav_files = (
+    ('wav/amen_22k16b_160bpm.wav', 1.0),
+    ('wav/dnb21580_22k16b_160bpm.wav', 0.9),
+    ('wav/drumloopA_22k16b_160bpm.wav', 1.0),
+    ('wav/femvoc_330662_22k16b_160bpm.wav', 0.8),
+    ('wav/scratch.wav', 0.5),
+    ('wav/pt_limor_modem_vox_01.wav', 0.4),
+    ('wav/snowpeaks_22k_s16.wav', 0.8),
+    ('wav/dnb21580_22k16b_160bpm_rev.wav', 1.0)
+)
+
+# pins used by keyboard
+KEY_PINS = (
+            board.RX, board.D2, board.D3, board.D4,
+            board.D5, board.D6, board.D7, board.D8
+)
+
+km = keypad.Keys( KEY_PINS, value_when_pressed=False, pull=True)
+
+audio = AudioOut( board.D10 )  # RP2040 PWM, use RC filter on breadboard
+mixer = audiomixer.Mixer(voice_count=len(wav_files), sample_rate=22050, channel_count=1,
+                         bits_per_sample=16, samples_signed=True)
+audio.play(mixer) # attach mixer to audio playback
+
+for i in range(len(wav_files)):  # start all samples at once for use w handle_mixer
+    wave = audiocore.WaveFile(open(wav_files[i][0],"rb"))
+    mixer.voice[i].play(wave, loop=True)
+    mixer.voice[i].level = 0
+
+def handle_mixer(num, pressed):
+    voice = mixer.voice[num]   # get mixer voice
+    if pressed:
+        voice.level = wav_files[num][1]  # play at level in wav_file list
+    else: # released
+        voice.level = 0  # mute it
+
+keys_pressed = []  # list of keys currently being pressed down
+
+
+while True:
+    event = km.events.get()
+    if event:
+        if event.key_number < len(wav_files):
+            if event.pressed:
+                handle_mixer(event.key_number, True)
+                keys_pressed.append( event.key_number )
+
+            if event.released:
+                handle_mixer( event.key_number, False )
+                keys_pressed.remove( event.key_number )

Breakbeat_Breadboard/wav/amen_22k16b_160bpm.wav

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+some sounds from freesound.org:
+- https://freesound.org/people/NoiseCollector/sounds/3667/
+- https://freesound.org/people/VEXST/sounds/24940/
+- https://freesound.org/people/djgriffin/sounds/21580/
+- https://freesound.org/people/womb_affliction/sounds/330662/